Cushion hitch device



May l 1951 o. w. GERMAN 2,551,457

CUSHION HITCH DEVICE Filed Dec. 18, 1948 2 Sheets-Sheet l m v J))))))))))))))))))))))))))))) .1 n?

IN VEN TOR. GREY w. OERMAN ORNEYS May 1, 1951 o. w. GERMAN 2,551,457

CUSHION HITCH DEVICE Filed Dec. 18. 1948 2 Sheets-Sheet 2 F 6 INVENToR.

OREY W. OERMAN Patented May l, 1951 UNITED STATES;

TENT O F F I CE ClllSl-IION HITGH" DEVICE Oreyl W. erman, Moline, Ill., assigner to Deere & Company, Moline, Ill., a. corporation ofl IlliY nois 12 Claims.

The presentY invention relatesy generally to agricultural machines and more particularly to hitch devices by whichy agricultural' implements are connected to a tractor or other means for propeiling them.

'The object and general naturer of the present invention is the provision of' a new and improved hitch device adapted. to be connected between an implement, such as a plow or the like, and a farm tractor to be utilized as a source of power for propelling the implement both in its working andi its transport positions. More specifically, it isa feature of this invention to provide a cushion hitch device so constructed' and arranged as to provide an extra long cushioning unit but without requiring excessive length inthe draf-t transmitting structure. Further, it is a. featurel of this invention to provide for the transmission of draft forces through a pair of springs arranged serially with a single spring whereby; during nor'- mal operation, the latter spring provides a cushioning action, but is constructed and arranged so that the extent of compression orl imposition of forces on the single spring element is limited by means of abutting parts, abutment of said parts then causing the entire draft pull to be transmitted through the pair off generally parallel springs.

In this connection, it is a.- further feature of this invention to provide new and improved means for disengaging the tractor clutch when the cushion hitch devicereferred to above is extended under abnormal loading, such as that in which there might be some tendency for the tractor to stall, tip up at the front end', or the like. More particularly, it. is a feature of this invention to provide a clutch releasing mecha,- nism which includes motion-multiplying means whereby the slack, usually necessary in hitches of this type to accommodate turning and the like, is taken up duringvv the rst. stageof yielding of the cushion hitch devicel and, moreover, the clutch disengaged during such rst stage. In a cushion hitch device as referred to above, the iirst stage oi yielding takes place when the intermediate member interposed between the two load-resisting spring means, moves upv against associated stops or the like. Motion of the clutch releasing mechanism at the end of this stage of yielding is such as tc release the tractor clutch. However, the cushion hitch device is. capable of further yielding in order tobring the tractor tov a standstill but withoutvrequiring the disconnection oi the hitch, andit is a further feature of the present invention in` this connection tov 2. provide a yielding element in the clutch operating: connections so as tor accommodate this secondv stage of' yielding ofthe hitch device under over--v load. Theprovision of. motion-multiplying means operative during the first. stage of yieldingv more than adequately secures the necessary amount of' movementY required for taking up the slack in the clutch actuating element and disengagingv the tractorY clutch. A further feature of this inven-v tion. isy the provision ofY clutch releasing connections so; constructed and arranged that the action ofthe motion-multiplying means terminates. at the end of theV first stageV of yielding of the; cushion hitch device, so that. the second stage of; yielding of the hitch device does not cause excessive movement of the clutch operating connections. but produces: only a reduced amount; ofmovement of the clutch` operating connections; By reducing the amount ofv movement of the,l clutch opera-ting connections during the second stage off yielding of the, cushion hitclr device. the: clutch-protecting yielding elementN ofY such con-- nectionsneednot be excessive-in length and may bea simple-spring.-

Thesefand other objects and advantages ofA the present invention will be apparent to those skilledf inA the: art after a. consideration off` the following detailed description, taken in conjunctionv withv the accompanying drawings, in which one form` y of' the invention; has been shown by wayoff illus-gv tractor,v with my improved cushion hitch and' clutch-disengaging connections, the latter being shown in their normal operating positions in. which the tractor clutch is engaged: whereby the tractor propels thel plowl and the clutch-disengaging connections are suiicientlyv slack to. accommodate the necessary1 turningand other relative movement between the plow: and tractor as encountered innormal operation.

Figure 2 is a fragmentary perspective show- 1, ing the connection of the clutch operating meansy with the conventional clutch lever of the tractor.

Figure 3 is an enlarged plan view showing the; .details of certain features of thef spring` cushion hitch deviceper se.

Figures: 4', 5' and 6` show the different positions ofthe cushion hitch; device and. theV associated' clutch operating connections.

Referring now toL the` drawings, particularly Figure l, the spring cushion hitch device of, the present invention is' indicated in'` its` entirety by the reference numeral I and is shown as connected between the drawbar 2 of a conventional farm tractor 3 and an agricultural implement 4, which is shown as a plow but which may be any other implement. The hitch unit I is of the spring-cushion type, that is, a type in which the transmission of pulling forces from the tractor to the implement is cushioned through the use of springs or the like, whereby both the tractor and the implement are protected from excessive loads due to abrupt changes in the draft forces transmitted, as may sometimes occur, for example, when the implement strikes a stone, root or the like. The hitch I also is of the type which affords a certain amount of cushioning during normal operation, but according to the principles of the present invention the tractor clutch is maintained in engaged position at all times until the amount of yielding, as under excess overloads, reaches a certain amount. The tractor 3 is provided with a main clutch of conventional construction, controlled by a hand operated clutch lever 5 which operates the tractor clutch through a link 6 (Figure 2). The tractor clutch mechanism is such that the hand lever 5 remains in either of its positions, that is engaged or disengaged, unless positively moved out of that position. Normally, the clutch lever 5 is moved forwardly to engage the clutch, as shown ln Figure 1, and rearwardly to disengage the clutch, which is the position shown in Figure 2. The tractor 3 is conventionally equipped with a pivot member supporting the clutch lever 5 for rocking movement on a lug 'I carried by the body of the tractor.

The spring cushion hitch unit I includes a main draft member II which preferably is made up of an upper angle member I2 and a lower strap member I3 connected together at their rear ends by a spacer I4 and at their forward ends by a block member I5 which is formed with apertured lateral extensions I6. The main draft member II is connected through suitable means, which includes a transverse bar I 8 and clevises I9, to the front end of the plow 4. The block member is apertured to receive a forward draft-transmitting member 2I which preferably is in the form of a fore and aft extending rod carrying at its rear end a slide block 23 and a cross bar 24, the latter extending at each side laterally outwardly beyond the slide or guide member 23. A heavy nut 25 on the rear end of the rod 2l transmits the forward pull from the rod 2| through the slide 23 to the cross bar 24. The ends of the cross bar 24 are apertured to receive a pair of side rods 26 which at their forward ends are connected by bolts 2'I to the lateral extensions I6 on the front block member I5.

AS best shown in Figure 3, an intermediate member 30 is mounted for sliding movement on both the rod member 2I and the side rods 26. The intermediate member 30 includes upper and lower plates 3I and 32, connected together b y a rear plate 33 which is apertured to receive the center rod member 2I and a pair of front plates 34 which are apertured to receive respectively the side rods 26. A pair of springs, each of which is indicated by the reference numeral 36, is disposed between the front plates 34 and the rear cross bar 24, the springs being disposed about the side rods 26. A third spring 3I is disposed about the center rod member 2| and lies between the rear plate 33 and the front block member I5.

vIn normal operation, the forward draft of the 4 tractor is transmitted to the front end of the rod member 2| and from the rear end of the latter member through the cross bar 24 and two springs 36 to the intermediate member 30. From the latter the draft force is transmitted through the rear block 33 to the rear end of the center spring 3'I, and from the front end of the latter to the front end of the main draft member II which is connected at its rear end to the plow 4. Preferably, the springs 36 and 31 are of substantially the same strength and all yield during the transmission of draft forces. However, since the two springs 36 are disposed in parallelism they yield only approximately half the amount that the front spring 3'! yields. When the single spring 3I approaches the limit of its permissive deflection, the front end of the intermediate member 3U comes up against the block member I5, thus terminating further yielding of the spring 3'I. However, continued yielding of the hitch device can take place by further compression in the springs 36. However, all normal operating loads are taken care of by yielding of all of the springs 36 and 3'I and the intermediate `member 36 does not normally come into contact with the block member I5 until the draft forces become excessive. During the normal cushioning movement of the hitch unit I, the main draft member II slides rearwardly along the center rod member 2| away from the block member I5, and since the spring 37 is compressed approximately twice the amount of compression in the springs 36, because the latter two act against the one spring 3'I, during the time the main draft member II slides a given amount rearwardly along the rod member 2l the intermediate member 30 slides rearwardly along the rod member 2I and the rods 26 a distance substantially equal only to two-thirds of the amount of rearward movement of the member II along the rod member 2I.

The clutch throwout mechanism, which is indicated in its entirety by the reference numeral 40, is especially constructed to respond to the relative movement between the intermediate member 30 and the main draft member I I and to disengage the tractor clutch for shifting the hand lever 5 rearwardly, substantially at or before the intermediate member engages the block member I5. The clutch throwout mechanism will now be described. Fixed to the angle member I2 is a pulley bracket 4I carrying suitable means upon which a sheave or pulley 42 is mounted for rotation. A bracket 4I is xed to the angle I2, as by bolts 43, and is positioned rearwardly of the front portion of the intermediate member 36. This portion of the latter member carries a bracket or lug 44, preferably Welded to the upper plate 3l, and the lug 44 carries a pin or bolt 45 to which the rear end of a flexible clutch-disengaging member, preferably in the form of a chain 46, is connected. The rear portion of the chain 45 is extended rearwardly and is trained over the pulley 42, then extends forwardly through a guide pulley 48 and thence forwardly over a guide pulley 5I which is carried by a bracket 52 xed by studs 53 to the forward side of the right hand axle quill 54 of the tractor.Y Beyond the pulley 5 I, the chain 46 extends upwardly and connects to the lower end of a spring 5I, the upper end of which is connected to an arm 58 which is fixed to the outer end of a sleeve 59, the inner end of which carries a clutch lever operating extension 6 I. The sleeve 59 is mounted on a pivot member 63 which is longer than and replaces the usual pivot that is carried by the tractor mg: 'l and rockably' receives; the hand'. clutch. lever 5.. Thefpivot member 632 is-y considerably longer than.. the conventionali pivot member and its outer endl is supported by ani adjustable brace member 65' which at its lower end is; connected to an apertured lug lillk xed tothe front portion or" the frontv pulley support. bracket 52. Preferably, the brace B5 consists of an upper rod 68 the lower end ofv which isthreaded.. into a vertically disposed adjustablev sleeve 69 that is connected by a bolt lv-I to the bracket extensiony 66.

The operation. of my' new' and. improved cushion hitch. and clutch-controlling connectionsubstantially as follows.

The normal. operating. position'. of. the.` several, parts is shown in Figure 1, in which th'ei clutch.- controlling chain 46.- includ'es. slack. suicient to accommodate turning:` movementor the' tractor.` relative to the implement and' any' other normal. variations in. the position of; the implement and'. tractor one with respect. tofthe. other.. UponA the occurrence of an.y overload of. suchmagnitude'r that it becomes desirable to disconnect the power, the' spring members 35 and 3l' yield. which. results. in a rearward: movement of' the. draft member lil? along: the draft rod 2l and additionally' a rear.'- ward movement. of the.. draf-t member ll: and: bracket 4l), carrying the' pulley 42,.relativei. to.l the intermediate member 3Q and. the. lug.' M carried. bythe latter.. As best shown in` Figures et andA 5, this movementY of the bracket 4t' relative to the; bracket d4 is multiplied'. byv the. chain andV she'ave' arrangement so that the. front. portionA oi the chain it is. moved rearwardly relative to; the. tractor a distance indicated at a'. in Figure. 5l which is. equal to. twice the amount: of movement of the member t! relative to the intermediate member 3Q', plus'. the amount or. rearward movement of the lug lll! relative tothe rod 2t.. The parts are so arranged that this movement is sufcient to take` up the slack inthe. ch'ai'rrll.l and act through. the spring.' 5.1; and. arm 5B; to. rock. the handlever 5 from its forward positionto'-v its rea-r'- ward position. thusr disengaging the'. tractor" clutch. As mentioned above,.however; thefcluftohi is disengaged substantially aty or* befores the' intermediate member 3l? engages; the block.' l5', which terminates any further compression in; the. spring 3,'1, and therefore terminates.' any further relativemovement between the. intermediate. member 3i! and the-main draft member. l i'. How.- ever, further extension ofy the hitclr unit I, as' indicated" by the distance.l b in Figure. is' pos:- sible by virtue-of further'compression of theV pair of springs 3S, which thus yield under additional excess overloading. As the springs 36' yield.I the main. draft member Il moves rearwardly' an ad'- ditional. amount along the rod member 21,. but this motion. is not multiplied by theA chain: and sheave arrangement since the intermediate member 35- now no longer moves relative to the draft member Il. Therefore, under the: excess overloading as accommodated by the springs: 3e, the chain 46 moves rearwardly relative tothe tractor only the same amount of movement, as indicated at b, as the hitch. and plow.` While this' movement is at a rate less than therate-of movement when the draft member l- Ir movesA relative' to the intermediate member 3Q, it. is or may be an". amount of movement that must be accommodated'. without damaging the tractor clutch4 and associated parts, and to this end the chain d'6 isA con-V nected to the clutch disengaging lever 5B1 through the spring 51.. Thus, the spring: 5:1.: yields to per'- 6 mit the. movement of; the chain 4.6 just menitimed'.

The" clutch operating' connections just described aref particularly adapted for use with a cushion hitch of the two-stagetype, and the'parts are. so arranged that during yielding in the first. sta-ge, the yielding motion is multiplied, and this'v n'rulti'p'l'iedv motion is'made usey ofl to disengage the tractor clutch. However, movement of the oper-V ating connections during the second stage of yielding,A as underA excessive overloads, is accommodated, by the resilient element in the clutch operating connections and is not multiplied.

While I have shown and described above the 1 preferred-.structure in which the principlesv of the presenti invention have been incorporated, it is to be understood that my invention is not to be limited to the exact details shown and described above, but that*y in fact, widely different means may be. employed in; the practice of the broader aspects of my' invention.

What I claim, therefore, and desire. to securer by'Letters Patent is:

1. For use in an agricultural outfit including a. propelling tractor having a releasable clutch and a towed implement connected to the tractor through a cushion hitch which includes two relatively' shiftable members, the

which. comprises two serially interconnected' i spring means adapted to be mounted on said hitch for yieldably resisting' relative movement-v between. said members, a parti disposed between said two spring means and movable under load relative to one. of said members when draft.

is applied to the other oit said members, and means cooperating with said part for. limiting movement thereof after one of said spring means' has been deflected a. predetermined amount', a clutch. release device comprising a member adapted to be: connected to disconnect said.

clutch, and motion-multiplying means. connectedwith said. part and adapted to. be connected with". said'. one ofi said relatively shiftable members; for. moving said clutch actuating member in a direction to release said clutch before said part engagesv said. limit means and at ar rate and extent. of movement greater` than the. rate and extent of relative movement of. said part and Said one relatively shiftable member.

2. For' use in, an. agricultural outt including-,-

a propelling tractorl havingy a releasable clutch and?. a towed implement connected to the tractor through a cushion hitch which includes two rel-- atively shiftable members; the improvement that comprises two serially interconnectedv spring means adapted to yieldably resist relative movement between said members, one of said members'being capable of transmitting a greater force per unit deiiectiony than the other and draft force of the tractor applied to one of said members being. first transmitted to said stronger spring means, thence to the other spring means' and. from. the latter to the other of said members, a part disposed between said two spring means. and movable under loads relative to saidv other of saidv relatively shiftable members, a sheave. carried' by said other member rearwardly of said part, a connection adapted to be established between said clutch and said part including' a exible sectionv extending' rearwardly to and around said s'heave and thence forwardly to said part, whereby a given amount. of rearward movement of saidother member relative tosaid one member causes substantially twice that amount of'v rearward movement of said clutch opimprovement,

7 i erating connection, stop means limiting the relative movement of said part relative to said other member whereby further relative movement between said members is accommodated by deection of said stronger spring means with no further movement of said part relative to said other member, and spring means in said clutch operating connection so as to accommodate a further extent of rearward movement of said other member and said part as a unit relative to said one member and the resultant rearward movement of said conection of the same extent without over-operation of said clutch.

3. For use in an agricultural outfit including a propelling tractor having a releasable clutch and a towed implement connected to the tractor through a cushion hitch which includes a main draft member connectible at its rear end to said implement, a draft part shiftable along said draft member and connectible at its forward end to said tractor, a cross member fixed to the rear end of said draft part, an intermediate member also shiftable relative to said main draft member, a pair of springs acting between said cross member and said intermediate member, and a single spring acting between said intermediate member and the front end of said main draft member, the improvement which includes a clutch release device comprising a pulley bracket adapted to be fixed to said main draft member rearwardly of said intermediate member, a pulley carried thereby, a second bracket adapted to be fixed to said intermediate member and movable away from said pulley bracket when yielding of said springs under load permits said intermediate member to move relative to said main draft member, a flexible clutch actuating connection secured at one end to said second bracket and adapted to extend rearwardly therefrom around said pulley and thence forwardly to the tractor' clutch, whereby rearward movement of said main draft member along said draft part causes a rearward movement of said clutch actuating connection which is substantially twice the amount of rearward movement of said main draft member relative to said intermediate member, said clutch actuating connection being adapted to be connected with the tractor clutch whereby said rearward movement of said clutch actuating connection disengages said clutch.

4. In an agricultural outfit including a propelling tractor having a releasable clutch and a towed implement connected to the tractor through a cushion hitch which includes a main draft member connectible at its rear end to said implement, a draft part shiftable along said draft member and connectible at its forward end to said tractor, a cross member fixed to the rear end of said draft part, an intermediate member also shiftable relative to said main draft member, a pair oi springs acting between said cross member and said intermediate member, and a single spring acting between said intermediate member and the front end of said main draft member, the combination therewith of a clutch release device comprising a pulley bracket fixed to said main draft member rearwardly of said intermediate member, a pulley carried thereby, a second bracket fixed to said intermediate member and movable away from said pulley bracket when yielding of said springs under load permits said intermediate member to move relative to said main draft member, a flexible clutch actuating connection secured at one end to said second bracket and extending rearwardly therefrom around said pulley and thence forwardly to the tractor clutch, whereby rearward movement of said main draft member along said draft part causes a rearward movement of said clutch actuating connection which is substantially twice the amount of rearward movement of said main draft member relative to said intermediate member, said clutch actuating connection being connected with the tractor clutch whereby said rearward movement of said clutch actuating connection disengages said clutch.

5. For use in an agricultural outfit including a propelling tractor having a releasable clutch and a towed implement connected to the tractor through a cushion hitch which includes a main draft member connectible at its rear end to said implement, the improvement which comprises a draft part .adapted to be mounted for shifting movement along said draft member and connectible at its forward end to said tractor, a cross member fixed to the rear end of said draft part, an intermediate member also adapted to be mounted for shifting movement relative to said main draft member, a pair of springs acting between said cross member and said intermediate member, and means to limit the amount of forward movement of said intermediate member relative to said main draft member, whereby during further rearward movement of said main draft member relative to said draft member, as under an overload, the draft is transmitted entirely by said pair of springs, a single spring acting between said intermediate member and the front end of said main draft member and dimensioned so as to yieldably hold said intermediate member rearwardly of said motion-limiting means, a clutch release device comprising a pulley bracket adapted to be fixed to said main draft member rearwardly of said intermediate mem'- ber, a pulley carried thereby, a second bracket adapted to be fixed to said intermediate member and movable away from said pulley bracket when yielding of said springs under load permits said intermediate member to move relative to saidf main draft member, a fiexible clutch actuating connection secured at one end to said second bracket and extending rearwardly therefrom' around said pulley and thence forwardly to the tractor clutch, whereby rearward movement of said main draft member along said draft part causes a rearward movement of said clutch actuating connection which is substantially twice the amount of rearward movement of said main draft member relative to said intermediate member, said clutch actuating connection being adapted to be connected with the tractor clutch whereby said rearward movement of said clutch actuating connection disengages said clutch, and spring means in said clutch actuating connection to accommodate further rearward movement of said connection and said main draft and intermediate members together relative to the tractor as the transmission of said overload forces causes further deflection of said pair of springs only.

6. For use in an agricultural outfit including a propelling tractor having a releasable clutch and a towed implement connected to the tractor through a cushion hitch which includes two relatively shiftable parts, the improvement which comprises a two-stage yielding means for resisting relative movement of said parts, a clutch release device comprising a member adapted to be connected to disconnect said clutch, motionmultiplying means adapted to be connected with said relatively shiftable parts and said member for moving the latter, at approximately twice the extent of yielding of said yielding means during the first stage of yielding thereof, to disengage said clutch, and spring means connected with said member and adapted to be connected with said clutch to accommodate further relative movement between said parts during the second stage of yielding of said yielding means,

7. For use in an agricultural outfit including a propelling tractor having a releasable clutch and a towed implement connected to the tractor through a cushion hitch which includes a pair of relatively movable parts, the improvement which comprises means for resisting relative movement therebetween in one direction including a pair of springs and a third spring arranged serially with respect to said pair of springs, and means for limiting the amount of stress imparted to said third spring, a clutch release device comprising a member adapted to be connected to disconnect said clutch, and means responsive to the yielding of only said third spring for shifting said member.

8. For use in an agricultural outfit including a propelling tractor having a releasable clutch and a towed implement connected to the tractor through a cushion hitch which includes a pair of relatively movable parts, the improvement which comprises means for resisting relative movement therebetween in one direction including a pair of springs and a third spring arranged serially with respect to said pair of springs, and means for limiting the amount of stress imparted to said third spring, a clutch release device comprising a member adapt-ed to be connected to disconnect said clutch, and motion-multiplying means connected to be responsive to the yielding of only said third spring for shifting said member.

9. For use in an agricultural outt including a propelling tractor having a releasable clutch and a towed implement connected to the tractor through a cushion hitch which includes a pair or" relatively movable parts, one adapted to receive the tractive pull and the other adapted to transmit the pull to an implement or the like, the improvement which comprises an intermediate member adapted to be disposed between said parts and shiftable relative to both, a pair o1" springs disposed generally in parallelism between said intermediate member and one of said parts, and a single spring acting be tween said intermediate member and the other of said parts, a clutch release device comprising a member adapted to be connected to disconnect said clutch, and motion-multiplying means connected with said intermediate member and responsive to yielding of said single spring for shifting said clutch operating member.

10. A hitch device adapted to connect an implement with a tractor having a releasable clutch, said hitch device comprising a main draft member, an intermediate member, and a draft part, all relatively shiftable with respect to one another, relatively strong spring means interposed between said part and said intermediate member, relatively weak spring means interposed between said intermediate member and said main draft member, means for connecting the latter to the implement, means for connecting said draft part to the tractor, and means responsive at least in part to rearward movement of said main draft member along said part relative to said intermediate member for releasing said clutch.

il. A hitch device adapted to connect an implement with a tractor having a releasable clutch, said hitch device comprising a main draft member, an intermediate member, and a draft part,

relatively shiftable with respect to one another, relatively strong spring means interposed between said part and said intermediate member, relatively weak spring means interposed between said intermediate member and said main draft member, means for connecting the latter to the implement, means for connecting said draft part to the tractor, and means responsive to rearward movement of said main draft mem- `ser along said part relative to said intermediate member for releasing said clutch, said responsive means including a yielding part to protect said clutch upon further movement of said main draft member along said draft part upon yieldof said relatively stronger spring means.

l2. A hitch device adapted to connect an irnplement with a tractor having a releasable clutch, said hitch device comprising a main draft member, an intermediate member, and a draft part, all reiatively shiftable with respect to one another, relatively strong spring means interposed between said part and said intermediate member, relatively weak spring means interposed between said intermediate member and said main draft member, means for connecting the latter to the implement, means for connecting said draft part to the tractor, means responsive to rearward movement of said main draft member along said part relative to said intermediate member for releasing said clutch, a pulley bracket in said main draft member, a pulley thereon, a iexible element connected at one end to said intermediate member and trained over said pulley and extending to the tractor, a pulley bracket on the tractor, a pulley on the latter bracket and receiving said element, a clutch operating member on the tractor including an arm receiving said element, a pivot receiving said clutch operating member, and a brace extending from the outer end of said pivot to said last men tioned pulley bracket.

OREY W. GERMAN.

REFERENCES CITED The following references are of record 'in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,305,651 Kaiser June 3, 1919 

